diff --git a/clang-tools-extra/clangd/CodeComplete.cpp b/clang-tools-extra/clangd/CodeComplete.cpp
index e0bfd120c1b0..19f33a40f889 100644
--- a/clang-tools-extra/clangd/CodeComplete.cpp
+++ b/clang-tools-extra/clangd/CodeComplete.cpp
@@ -1105,14 +1105,19 @@ void loadMainFilePreambleMacros(const Preprocessor &PP,
   ExternalPreprocessorSource *PreambleMacros = PP.getExternalSource();
   // As we have the names of the macros, we can look up their IdentifierInfo
   // and then use this to load just the macros we want.
+  const auto &ITable = PP.getIdentifierTable();
   IdentifierInfoLookup *PreambleIdentifiers =
-      PP.getIdentifierTable().getExternalIdentifierLookup();
+      ITable.getExternalIdentifierLookup();
+
   if (!PreambleIdentifiers || !PreambleMacros)
     return;
-  for (const auto &MacroName : Preamble.Macros.Names)
+  for (const auto &MacroName : Preamble.Macros.Names) {
+    if (ITable.find(MacroName.getKey()) != ITable.end())
+      continue;
     if (auto *II = PreambleIdentifiers->get(MacroName.getKey()))
       if (II->isOutOfDate())
         PreambleMacros->updateOutOfDateIdentifier(*II);
+  }
 }
 
 // Invokes Sema code completion on a file.
diff --git a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
index a57ae49f9159..e4e56f2b5e38 100644
--- a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
+++ b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
@@ -3139,6 +3139,15 @@ TEST(CompletionTest, FunctionArgsExist) {
                      Kind(CompletionItemKind::Constructor))));
 }
 
+TEST(CompletionTest, NoCrashDueToMacroOrdering) {
+  EXPECT_THAT(completions(R"cpp(
+    #define ECHO(X) X
+    #define ECHO2(X) ECHO(X)
+    int finish_preamble = EC^HO(2);)cpp")
+                  .Completions,
+              UnorderedElementsAre(Labeled("ECHO(X)"), Labeled("ECHO2(X)")));
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang